Bell County is a county located in the U.S. state of Texas. As of the 2010 census, its population was 310,235. Its county seat is Belton. The county was founded in 1850 and is named for Peter Hansborough Bell, the third governor of Texas.Bell County is part of the Killeen–Temple, TX Metropolitan Statistical Area.In 2010, the center of population of Texas was located in Bell County, near the town of Holland.